English

Completely non unitary contractions and Analyticity

Functional Analysis 2023-08-23 v2

Abstract

We study completely non-unitary contractions TT with finite dimensional defect spaces DT\mathcal{D}_T and DT\mathcal{D}_{T^*}. We present a complete classification of all such contractions TT that satisfy a generalized property of Hardy shift operator: DTDT\mathcal{D}_T\subseteq\mathcal{D}_{T^*}. We show that TT is analytic if and only if it has no non-zero eigenvalue. Furthermore, we characterize the hyponormality of all those TT.

Keywords

Cite

@article{arxiv.2307.12373,
  title  = {Completely non unitary contractions and Analyticity},
  author = {Susmita Das},
  journal= {arXiv preprint arXiv:2307.12373},
  year   = {2023}
}

Comments

22 pages

R2 v1 2026-06-28T11:38:04.912Z